Roly, Just had a brainwave re the heavy old stepdown transformer in this PA. Couldn't I swap it for a new lighter model ? This amp is rated at 150W. What would you suggest ?

Peavey PA-100 problem seems to be fixed  :dbtu:

Thanks so much for all your patience and input. I'm so glad this forum turned up in a web search and that I didn't spear off and replace all the transistors.

Through the combined effort of members help with fault finding it's been on test for 2 hours without any static. I've put a loop pedal thru all channels and they sound fine. Should I leave it on test any longer to be on the safe side ?

What I did was two things suggested 1) metho on transistors ~ no change in static 2) pushing the board down at various places gave me *heaps* of static around the driver stage transformer. Also wiggling the reverb connections where they join the board with "pins&socket" gave increased static.

Dumb luck fix ~ I re-soldered the "tabs" that connect the transformer to the board along with where the pins for reverb connection are.

So here's a photo of the board. I've marked the re-soldered points with an arrow.

Just wondering if the points I've marked as 1, 2 & 3 which are the red wire contacts from output transformer should be re-soldered as I think they may have made a noise when I was pushed on that section of board. Although they seem ok now.

Check out the date 12/76 almost vintage :lmao:   BTW the *vintage* 240v to 110v converter in this thing is a monster when it comes to moving it around. They sure did make them substantial back then.

Hadn't thought of that. Better still, get off the plane in Patagonia and take the train to New York ! :tu:

Thanks Enzo, Roly et al all very helpful. I'm certainly going to have to read and digest this info.

Roly, I live south of Murwillumbah Nth Coast NSW near one of those villages that consist of only a post office/ general store/ garage called Burringbar. I've gone into hiding to escape former students  8|

Over the next while I'll try some fault finding.

When the master volume is at zero the amp has static. Static starts as amp warms up  

Attached are a pic of the back of the amp. Also a component [ approx 7mm x 30mm, brown with one grey & one black stripe ] I found under the two large capacitors in what I now know to be the driver stage. It looks like it's leaking a fine machine oil.

Could this be contributing to the problem ?

Thanks for the info but I'm such a novice that I wouldn't know where to find those components at this stage.

Maybe you could give me a rough idea what section of the board they're on from the photos ?

What does freezing these components do ?

Thanks for the positive support guys. I really appreciate the welcome. :dbtu: 

Being a newly retired high school teacher [ workshop / manual arts / materials design etc] I have time on my hands. I can solder and know some basics of using a multimeter. I've been building electric and acoustic guitars for the last ten years in my spare time. 

I live in rural Australia with the closest tech a 1hr drive away. He had the PA for 2mths and charged me $110 for "servicing" ie replacing four capacitors. When I got it home it had the same problem so I rang him and that's when he told me he would have to "do a blanket replacement of the transistors".

Replaced caps are:   1 x 100v 220uF      2 x 63v 100uF   1 x 35v 68uF 

Original caps seem to be in good condition from outer appearances ie no leaking or discolouration.  The two big 50v 2200uF  caps seem in good condition but should I resolder them in case of poor joint ?

I've attached the schematic and some general view photos of this amp.

I've had this 1980's SS Peavey PA 100 for longer than I can remember.

It started to develop a lot of loud static ie pops & crackles even with all pots at zero. This static makes the PA useless for say a low volume level vocal / guitar etc. Increase in PA volume doesn't affect the static volume so it's ok for high volume performance. Not every wants the musicians blowing them away

Took it to a tech who says that he'd have to start at replacing all the transistors, which would add up to many hrs and cost $400 or so.
His advice was to junk it and buy another PA.

Thought I could do the transistors myself. The problem I have is as a newbie to involved electronics [ I can do guitar electrics etc ] when I started to check out
how and which transistors to replace I realised I don't know enough. I found that Peavey has a list of replacement transistors but I found that the original and the suggested replacement have different Base wires eg existing transistor has Base as middle but replacement has Base as left side wire. See attached diagram.

A number of replacement transistors have different base wires to the original so that's got me really confused.

Any help would be great as I don't want to junk this PA. Also haven't got the money for another better one.